Chain hoist



CHAIN HOIST Feb. l, 1944. C.;l BENJAMlN 2,340,409

CHAIN HOIST Filed Aug. 8, 1941 3 Sheets-Sheet 3 mvENTnR l .man se: w.BENJAMIN Y L7 ffm? ATT' HNEY Patented Feb. 1, 1944 HQISTR,

`George W. Benjamin, Birmingham, IAla., assignoi' to Continental GinCompany, acorpo'ratin of Delaware Application August 8, 194i,` SerialNo. 496,1136

4 Claims.

My invention relates to a chain hoist of the type embodying a' 'ratchet31H51. leve? mechafnm for advancing` or retractingl a chain, one link ata time, ina suitable guicleway, andl in particular is an improvement' nthe hoist described and claimed in my prior Patent No. 2,227,893, issuedJanuary 7, 1941.

The principal object of my inventionis to provide a simple, sturdy hoistof the character described which shall have improved operatingcharacteristics over that of my prior patent.

In my prior patent aforesaid, I employ an 'operating lever pivoted onthe'body ofthe' hoist and I pivotally mount a pawl Aon each side of thepivot point of the lever, they pawls being adapted to'engage the linksoi a chain alternately to advance or retract it with respect to the bodyof the hoist. The pawls are biased towardthe chain when lifting and areVso vshaped that when one pawl engages aflinkto advance it, the otherpawl isH caused to disengag itsA associated and permit the lchain"toadvancef While the apparatus of my said patent'` is entirely successfulin operation, it has""the disadvantage that it is double acting andtheoperator must change his stance for eachv change of direction ofmovement of the lever.' That is,fin lifting a load theoperator must'raise the operating lever on one stroke and pull it` downwards on thenext stroke,v with an equal load in each direction, which operation isawkward and difiicult, particularly in handling heavy loads. e"

In accordance with my present invention, I employ `a hoist bodysimilar'to'that 'of my prior patent with an oscillating lever pivotallymounted thereon. Instead of mounting both pawls on rthe operating lever,I mount one on the lever and one on the' body of the hoist. The pawlsare resiliently connected to bias them towards the hoist chain. Withonly one pawl movable with respect to the bodyof the hoist, the chain isadvanced only upon movement of the lever in one direction. When thelever is movedA in the opposite direction, the paWl mounted onV the bodyof the hoist holds the 'chain while the' novable pawl engages another,link tot the chain. The

apparatus may thns be `,operated byexerting force in one direction onlyon the operatinglever. With a vertical lift, the work lstrokeis madedownwards, and it will at once be apparentftlat this is a distinctloads.

Apparatus embodying features of my invention is illustrated in theaccompanying--drawin'gs forming a par# of this appucanenin' whiehfff `50advantage in handling refait Fig.v1 is a View partly in section andpartly 1in elevation Showing'my imprwed heist; Fig. 2fisA a sectionalview taken along the line lII--lI 'of'Fieflf fig. 43 is a sectionalelevation taken at right angles to Fig. 1,; ""Fig, 4 'is` a fragmentaryelevation of the hoist showingfit arranged"forretracting the. chain;

A1'i`g.'5 is a sectional view drawn to a larger scale" showing theaction of the hoist in retractfingmthe'chain `at the moment before loadis tf Sierre@ fieri the' holiieg rawl' i@ ,the 'lifting bet/1:

1li-igt 6 is an elevational view of the holding pawn i f `F`ig. `'l isan elevational View showing the action ofthe hoistfinlowering .the chainat the moment before load is transferred frorn'the lifting Vpawl to theholding pa'wl andshowing the lifting bliant/l in "fotted position afterthe load is transferred; and ""Iig. 8 is a View showing the positions ofthe pawls whenlovveringthe'chain and when the operating lever isin"horizontalpositiom Referring to the'drgwing'sfr'a betterunderfstanding of my invention, vIfny improved hoist zormrises"a ldodyIll'prvided with 'a sustaining hook Il." Formed in the body I0 isaguideway ll2 for a chain I3'. 'lllhe chain I3 may beY of th flat,or'ladder type as shown, with cross pins f4 'connecting the 'separatelinks, crit may be' `of anytsuitable type "which may be engaged by aypaw-l and advanced in the manner hereinatte'r described. U'Ihe lowerend of the chain |3`l's adptedjto be attached tothe workV as by a hook16', partiauy shown irl Fig. `1'. .Bivotal'ly mounted on the body I0 isan operating lever lihaving 'arms I8' andy AI9 straddling thebody Il)and pvted `on pins' 21| `and 22 which may ,befbosselsformed on' thesidesof the body. A lifting pawl 23`is"pivoted at one vend 24 tothe arms la`and le of the operating lever l1, and egitends npwardl'y,A as `viewedin thedrawings, ,aloA id e the body A finger 2B formedl 6h th pay/1 zatxtends through 'an opening'zi thfe body .td engag a cross pin i4' ofthe chain Icaria ,move meenam witninthe body responsive to downwardmovement of the lever Il. 'Ihe underV side ofv the finger' is inclinedat Z8ffto cause it to engage Athenext' 'lower cross pin |14 and be movedout of the body l0,"uDoIn nievement of the ieyef l1 inthe oppositedimentico j` Eormed' on' ther body ID onthside OOSite the`,pawl"23 areapair of lugs 294 between' which is pivoted ,a Asecon@ `or locking new.;3l" Wbih 'is similar in configuration to the pawl 23 and which isprovided with a finger 32 adapted to enter the body I3 through asuitable opening at 33 and engage a cross pin I4 ofthe chain I3 to holdthe chain in any set position. The pawl 3| isk also provided with aninclined face 35 which, upon upward movement of the chain I3, as viewedin Fig. 1, causes the pawl 3| to be moved outwardly of the body il andassume a position to engage the next cross pin when it comes intoposition just above the finger 32.

Carried by the pawl 23 is a pin 34 and carried by the pawl 3| is a pin36, which pins are connected by a spring 31 which normally biases thepawls 23 and 3| inwardly of the body of the hoist to engage the crosspins I4. As so far described, when the operating lever I1 is raised fromthe position shown in Fig. 1 of the drawings, the pawl 23 movesdownwards while the finger 32 of the paw13| engages a cross pin I4 ofthe chain |3 to hold it in position in the body I0. The finger of thepawl 32 engaging the next lower pin I4 causes pawl 3| to ride over thatpin and when it has passed the pin it is pulled into position beneaththe pin by the spring 31. If the operating lever be now pulleddownwards, the finger 26 engages the last mentioned pin I4 and moves itupwards, while the pawl 3| pivoted to the side of the body I3 of thehoist is disengaged from the next lower pin I4 and is caused to moveoutwardly of the body I3 by the approaching pin I4, to engage it as soonas it passes above the finger 32. The chain and its load is thus raiseda link at a time by oscillation of the operating lever l1 and the pawl3| acts to hold the chain in itsraised position while the operatinglever I1 is being moved upwards to engage another link. Fingers 38 and3Q on the opposite ends of the pawls 23 and 3| respectively serve as ameans to disengage both pawls from the chain I3 when getting ready tooperate and it is desired to move the chain through the body aconsiderable distance without oscillating the lever |1.

Mounted on one side of the lever I1 and secured Vthereto preferably bywelding is a plate 4| having an oblong opening 42 therein with a notch43 in the plate giving access to the opening. Disposed midwayoi the endsof the spring 31 is a T-shaped member fill with the head ofthe T withinthe coils ofthe spring 31 and the shank 46 extending outwardly throughthe coils. When raising a load with the hoist, as just described, theshank 45 of the T is turned to the position shown in Figs. l and 3, thatis, out of engagement with the sides of the opening 42 in the plate 4|.When it is desired to lower a load gradually, the pin 46 is turned tothe position shown in Figs. 4' and 5 of the drawings, with the shank 46passed through the notch 43 into the opening 42. The shank 43 can bethus entered when the lever I1 is moved to mid position and will beengaged by the end of the opening i2 to compress one end of the spring31 when the lever I1 is in its lower position. With the shank 43 of theT-member `44 in the opening 42, and with the operating lever ZI1 in theposition shown in Fig. 5, it will be seen that the end of the spring 31attached to the pawl 23 is in tension while the other end attached tothepawl 3|, is incompression, tending to push thejflnger 32 of the pawl3| out of engagement with the cross pin I4. At this moment in the cycle'of operation, the finger 32 is held in engagement with cross pin I4 bythe weight of the load von said cross pin.

If the lever Il be now 'moved downward slight- Cil ly from the positionshown, the pawl 23 will raise the chain enough to release the engagementof thenger 32 of holding pawl 3| with its associated pin I4 and the pawlwill be moved out of engagement with the chain by the spring 31,permitting the chain to be lowered by gravity as the operating lever I1is raised. See Fig. 8. As the lever I1 is being raised, the engagementof the left end of the opening 42 with the shank 46 is relieved. SeeFig. 5. The end of the spring -31 attached to the pawl 3| is again putin tension and pulls the pawl inwardly of the housing I to engage withthe next higher cross pin I4,

i thus lowering the chain I3 one link.

At the saine time, as the lever I1 approaches its highest position, theright hand end of slot 42, as viewed in Fig. 7, engages the shank 46 andplaces the left end of spning 31 in compression. As soon as the leverhas been raised suiiciently for the holding pawl 3| to engage theadjacent descending pin I4v and take over the load, thepartrof spring 31in compression acts on lifting pawl 23 toY move it outwardly of housingIii and out of engagement with the chain, as shown in dotted position,Fig. 7. The lever I- may now be lowered and spring 31 will hold liftingpawl 23 out of engagement with the chain until it has passed the pin I4with which it has been engaged, at which time the slot 42 will havemoved out of engagement with shank 46 permitting spring 31yto pull pawl23 back into the housing to engageY with the next higher pin Ill, asAshown in Fig. 8.

While in the description herein the action of the hoist has beendescribed as when raising or lowering Va load, it will be obvious thatthe action is the vsame when acting on a horizontal pull as whenstretchingV or loosening a wire or cable.

From the foregoing it will be apparent that I have devised' an improvedchain hoist which is simple and sturdy of design and which is easilyoperated without the operator being obliged to change his positionduring the operation.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptible'of various changes and modifications, without departing fromV thespirit thereof, and I desire, therefore, vthat only suchV limitationsshall be placed thereupon as are spccically set forth in' the appendedclaims.

What I claim is:

1. A'chain hoist comprising a housing, a chain nrovably mounted in thehousing and adapted for attachment at one eridto a load, a locking pawlpivotally `mounted on the housing and adapted tol engage "the chain andprevent retraction thereof, a lever pivoted to the housing, a pawlpivoted to the lever and adapted to push the chain through the housingwhen the lever is osciilated, andY aV spring for biasing the pawlstoward engagement with the chain, and means adapted to coact with thespring and the lever alternately to effect disengagement of said pawlswhen retracting the chain'.

'2. A chain hoist comprising a housing having a longitudinallyextendingy guideway, a chain movable through the guideway and adaptedfor attachment at one end to a load, alocking element pivoted to thehousing and having a portion adapted to engageV the chain and preventrearward retraction thereof, an operating lever, pivoted to the housing,apawl pivoted to the lever and adapted to feedthe chain through theguideway upon oscillation of the lever, a spring con# nected to thelocking element and the pawl and biasing them toward engagement with thechain, and means associated with the spring and the lever for exertingforce alternately on the locking element and the pawl to disengage thema1- ternately from the chain during lowering operation.

3. A chain hoist comprising a housing having formed therein alongitudinally extending guideway, a chain slidable in the guideway, apawl pivotally mounted on a side of the housing and adapted normally tolock the chain against rearward retraction during operating, a leverpivoted to the housing, a second pawl pivoted to the lever and engagingthe chain on the side thereof opposite to the rst mentioned pawl, saidsecond pawl being adapted to push the chain through the housing uponmovement of the lever about its pivot, a spring to bias the pawls intochain engaging position, a member carried by the spring and engaging thecoils intermediate the ends, said member being movable into the path ofthe lever, and means on the lever adapted to coact with the said memberto exert a force alternately on the locking pawl and said second pawl todisengage them from the chain during lowering operation.

4. A device of the character described comprising a housing havingformed therein a longitudinally extending guideway, a chain movable inthe guidewatr and adapted for connection at one end to a load, a pair ofpawls entering between the links of the chain on opposite sides thereof,means to pivotally mount one of the pawls on the housing, an operatinglever pivoted adjacent one end to the housing and having a handleportion and an extension portion, means to pivotally mount the other ofsaid pawls on the extension portion of the lever, means for biasing saidpawls into chain engaging position, and

` means responsive to operation of the lever during `lowering operationto engage the biasing means and eiect alternate disengagements of thepawls therefrom.

GEORGE W. BENJAMIN.

